The present invention relates generally to dice location identification on a wafer, and more specifically, to a method of forming the location indicia on the dice on a wafer.
It is often desirable to identify the area of a wafer from which a particular die has come. Some military contracts even require wafer quadrant identification to be maintained throughout the assembly and lot qualification procedure. The importance of identifying the failed or defective dice relative to their location on a wafer aids in the analysis of the processing steps and correction thereto. For example, the malfunction or failure of devices on a chip may be results from uneven temperature or temperature gradients across the wafer during processing. Similarly, by providing identifications even on the quadrant level allows rejection of one quarter of the dice on a wafer instead of all of the dice on a wafer if a fixed percentage of dice fail qualifying test or malfunction.
Heretofore no viable method has been provided to achieve wafer location identifying indicia on the chip.